The present invention relates to the general field of aircraft turboprops having two unducted propellers. The invention relates more precisely to attaching such a turboprop to a structural element of the aircraft, such as the fuselage or a wing or an airplane.
In known manner, an aircraft turboprop having two propellers is an aeroengine in which the main thrust is generated by two contrarotating propellers that are not ducted and that are positioned at the rear of the engine.
By way of example, such a turboprop may be attached to the fuselage of an aircraft by means of a pylon that is connected to a suspension structure, which suspension structure is directly fastened to the engine.
The suspension structure of such a turboprop needs in particular to be capable of withstanding the thrust forces from the engine and the rotary torque from the propellers. For this purpose, its architecture must enable it to reduce the loads and the accelerations that are transmitted to the aircraft, and also the effects of casing distortion in order to improve performance. Furthermore, the suspension structure needs to be optimized in order to limit the static and dynamic loads seen by the engine so as to be able to limit its weight. Finally, the architecture of the suspension structure must make it possible to conserve enough space to leave room to install the external configuration of the engine (i.e. auxiliary equipment, pipework, and harnesses).
Thus, the way a turboprop is attached to a structural element of an aircraft has a direct influence on the behavior and the performance of the engine, and therefore constitutes a line of research and endeavor for engine manufacturers.
Furthermore, this influence of the attachment of the turboprop is particularly important for turboprop architectures of the type comprising two unducted contrarotating propellers, where additional difficulties are present. In particular, such engines present a considerable overhang, thereby leading to phenomena of engine casing distortion. Likewise, engine loads are greater as a result of the engines generally being mounted at the rear of a fuselage by means of pylons of large dimensions. In addition, installing auxiliary equipment on such engines can lead to problems with conventional pylons.